Variable thickness control for veneer lathe

ABSTRACT

The control includes a series of solenoid valve-controlled air cylinders which actuate shift bars to shift preselected gears of a multiple ratio gear box to transmit motive power to a knife carriage and thereby feed a veneer knife into a log at preselected variable speeds to peel veneer from the log at a desired thickness. A roller bar spaced from the knife can be shifted at a fast speed relative to the knife to adjust quickly the horizontal spacing between the knife and the bar when changing the feed rate of the knife. The roller bar can also be shifted slowly relative to the knife to vary the pressure applied by the roller bar to the veneer as it is peeled. Solenoid valvecontrolled hydraulic cylinders shift the carriage mounting the roller bar vertically between upper and lower adjustable stops to change quickly the vertical spacing between the roller bar and knife when the knife speed is changed. A common manually operated remote control makes all three adjustments of the thickness settings simultaneously.

United States Patent Daniels et al.

[ Aug. 1, 1972 [54] VARIABLE THICKNESS CONTROL FOR VENEER LATHE [72]Inventors; Curtice F. Daniels, PO. Box 302,

Glendale, Oreg. 97442; Curtice F.

Daniels, Jr., 1311 NW. Hawthorne, Grants Pass, Oreg. '97526 [22] Filed:July 6, 1970 [21] Appl. No.: 52,491

Primary Examiner-Donald R. Schran Attorney-Buckhorn, Blore, Klarquist &Sparkman [57] ABSTRACT The control includes a series of solenoidvalve-controlled air cylinders which actuate shift bars to shiftpreselected gears of a multiple ratio gear box to transmit motive powerto a knife carriage and thereby feed a veneer knife into a log atpreselected variable speeds to peel veneer from the log at a desiredthickness. A roller bar spaced from the knife can be shifted at a fastspeed relative to the knife to adjust quickly the horizontal spacingbetween the knife and the bar when changing the feed rate of the knife.The roller bar can also be shifted slowly relative to the knife to varythe pressure applied by the roller bar to the veneer as it is peeled.Solenoid valve-controlled hydraulic cylinders shift the carriagemounting the roller bar vertically between upper and lower adjustablestops to change quickly the vertical spacing between the roller bar andknife when the knife speed is changed. A common manually operated remotecontrol makes all three adjustments of the thickness settingssimultaneously.

17 Claims, 11 Drawing Figures PATENTEDAus 1 m2 SHEET 1 0F 6 m/WF MI L- TL W M 7 8 M 3 4 O 3 0 %4 2 44 1 4 I B 2 m m 'Iulllll fi ll l-LL LllILINVENTORS.

BUCKHORN, BLORE, KLARQUIST 8. SPARKMAN ATTORNEYS PATENTEDMIS 1 Ian sum 20r 6 FIG. ll

CURTICE F DANIELS- CURTICE F DANIELS, JR

INVENTORS.

BUCKHORN, BLORE, KLARQUIST & SPARKMAN ATTQRNFYS VARIABLE THICKNESSCONTROL FOR VENEER LATHE BACKGROUND OF THE INVENTION 1. Field of theInvention The present invention relates to a control for a veneer lathewhereby the lathe can be adjusted quickly to change the thickness ofveneer peeled from a log.

2. Description of the Prior Art In the past a great amount of time wasrequired to change the thickness settings of a veneer lathe. Because ofthis, it has been common practice to peel a given log at a constantthickness. The thickness of peel was determined by visual inspectionfrom the outside appearance of the log. If the log appeared to have veryfew defects, it would be peeled so as to produce a valuable .thinsurface grade veneer. If the log appeared to have many defects, it wouldbe peeled so as to produce a relatively thick, inferior core gradeveneer. However, if the lathe was set to produce a thin peel andnumerous defects showed up unexpectedly in the interior of the log, muchof the peel would be unusable as veneer and would therefore be wasted.On the other hand, if the lathe was set for a thick peel but theinterior of the log turned out unexpectedly to be of sufficiently highquality to produce surface grade veneer, much potential production ofthis highly valuable surface grade veneer was lost.

In changing thickness settings of a veneer lathe three adjustments arenecessary, namely (1) a change in the feed rate of the veneer knife intothe log; (2) a change in the horizontal spacing between the veneer knifeand the roller bar; and (3) a change in the vertical spacing between theroller bar and the knife.

In the past several attempts have been made to solve the problem ofreducing the time required to change thickness settings of a veneerlathe. However, no prior art devices suggested for this purpose arecapable of making more than one of the above necessary adjustmentssufficiently fast to justify economically varying the thickness of peelfrom a single log. For example, the prior art Cremona US. Pat. No.3,473,585 discloses an apparatus for changing only the horizontalspacing between the veneer knife and the roller bar. On the other hand,Nagaoka US. Pat. No. 3,349,820 discloses an apparatus suitable only forchanging the horizontal feed rate of the knife.

Thus there is still a need for a control system capable of makingquickly all of the lathe adjustments necessary to change the thicknessof pee] without impairing the dimensional accuracy or quality of thepeel.

SUMMARY OF THE INVENTION The present invention overcomes the problems ofthe prior art in providing a variable thickness control enabling almostinstantaneous adjustment of the thickness settings of a veneer lathe tovary the thickness of peel between a predetermined thin setting and apredetermined thick setting. This enables both core grade and surfacegrade veneer to be peeled from a single log as dictated by the conditionof the portion of the log being peeled at any given time.

The thickness control of the invention maximizes the economic value ofveneer which can be peeled from a single log.

The control minimizes the amount of production time lost in changingfrom one thickness setting to another. The control minimizes the amountof waste produced in peeling a log.

The control minimizes the amount of production time lost in changingfrom one thickness setting to another.

The control also takes most of the guesswork out of grading a log todetermine whether to peel it at a thick setting or a thin setting of thelathe.

Furthermore the control is adaptable to existing lathes, making itunnecessary to purchase an expensive new lathe to receive the benefitsof the invention.

More specific objects and features of the invention include:

1. means for changing quickly the feed rate of the veneer knife into thelog;

2. means for changing quickly the vertical spacing between the rollerbar and the veneer knife;

3. means for changing quickly the horizontal spacing between the rollerbar and the veneer knife;

4. means for effecting all three of the foregoing changes substantiallyat the same time;

5. a manually operable remote control for effecting all three changessimultaneously;

6. a remote control including a single control member which effectuatesall three adjustments simultaneously.

BRIEF DESCRIPTION OF THE DRAWINGS The foregoing and other objects,features and advantages of the present invention will become moreapparent from the following detailed description which proceeds withreference to the accompanying drawings wherein:

FIG. 1 is a schematic view of a veneer lathe incorporating the controlsystem of the present invention;

FIG. 2 is a partial front elevational view of a veneer lathe withportions broken away to illustrate portions of the control system; box

FIG. 3 is a schematic view of a two-speed gear box used as part of thetransmission in the system of FIG. 1;

FIG. 4 is a schematic view of a ratio gear box used in conjunction withthe two-speed gear box of FIG. 3;

FIG. 5 is a schematic plan view of a first portion of a shiftingarrangement for shifting gears in the gear box of FIG. 4;

FIG. 6 is a second portion of the shifting arrangement for shiftinggears in the gear box of FIG. 4;

FIG. 7 is a diagram of the air circuit for the control system of FIG. 1;

FIG. 8 is a diagram of the hydraulic circuit for the control system ofFIG. 1;

FIG. 9 is a diagram of an electrical circuit for the control system ofFIG. 1;

FIG. 10 is a schematic elevational view of the transmission shown inFIGS. 3 through 6; and

FIG. 11 is a partial top view of the veneer lathe of FIG. 2 showing aportion of the horizontal drive for the roller bar.

described with reference to a conventional veneer lathe such as, forexample, a Model 244 lathe manufalitiired by the Coe ManufacturingCompany of Painesville, Ohio. Such lathes normally do not come equippedwith the control system to be described but, in accordance with theinvention, they can be readily converted to incorporate such system.Such lathe is typical of a conventional veneer lathe in that it includesa stationary main frame mounting a chuck 12 for rotating a peeler log Lin a direction indicated by the arrow 14 in FIG. 1. A veneer knife 16 ismounted on a knife carriage 18 which in turn is mounted on a bed portionof the frame for sliding movement toward and away from the chuck.

The knife carriage 18 is movable in a horizontal direction to feed knife16 into the log by a motor 20 through a transmission which includes amultiple speed gear box arrangement 22 transmitting motive power througha worm shaft 24 to a nut member 26 on the knife carriage.

The lathealso includes a rotatable roller or pressure bar 28 spacedabove-knife 16 for applying a variable pressure to the back side of theveneer V as it is peeled from the log by knife 16. The spacing of rollerbar 28 both horizontally and vertically with respect to knife 16 dependson the desired thickness of the veneer peeled from the log. For arelatively thin veneer the roller bar is positioned vertically closer tothe knife and horizontally closer to the log than for a thick veneerpeel. Thus roller bar 28 is mounted for vertical and horizontaladjustment relative to knife 16. For this purpose the roller bar ismounted on a carriage head or subcarriage 30. The head in turn ismounted on knife carriage 18 in a manner permitting horizontalmovementof the head relative to the carriage 18 and thereby horizontaladjustment of the roller bar 28 relative to the knife. The

head is also mounted on the carriage in a manner permitting verticaladjustment'of the head relative to the carriage 18 and thereby verticaladjustment of the roller bar 28 relative to knife 16.

Referring to FIGS. 1 and 11, the means for moving head 30 and thusroller bar 28 horizontally relative to the knife includes an electricmotor 32 driving a worm shaft 34 through a chain-and-sprocket drive 36.The worm shaft 34 extends through a nut 38 forming part of head 30.

' The means for changing the vertical spacing between the roller bar 28and knife 16 includes a pair of vertically spaced-apart set screws 40,41 at each side of the knife carriage threaded through portions 42, 43of knife carriage 18 as shown in FIGS. 1 and 2. A portion 44 of carriagehead 30 extends between each pair of set screws. Prior to the controlsystem of the present invention, the two set screwscomprised the solemeans of determining the vertical adjustment of roller bar 28 relativeto knife 16. Naturally this adjustment was time consuming and had tobedone manually.

a a drive chain 48,-a first sprocket 49 on motor drive shaft 50 and asecond sprocket 51 on an end portion of the roller bar.

Gear box arrangement 22 includes a two-speed gear box and a so-calleddecimal gear box 54, with the latter superimposed on the former as shownin FIG. 10.

The decimal gear. box can provide while countel'slnftdiffesentgearratiosllhetwo-speedgeu-boxprovldesa.

highmdlowspeednnge.'1hus,togetherthetwogear boxes provide up to 200different speeds and therefore i the same number of possible thicknessesof peel.

The decimal gear box is shown schematically in FIG. 4. It includes aninput shaft 56, output shafi 58 and two countershafts 60 and 62.Countershaft 60 is on the soshifting fork (not shown) The differentialspeed.

between the two countershafts resulting from the selected gear ratios onthe A and B shafts is transmitted from the countershafts through a trainof gears 61, 63, 65 to pinion gears 69 which thereby rotate output shaft8.

decimalgear box through an output gear of the twospeed gear box and aninput gear 57 of the decimal gear box, such gears being constantly inmesh.

As described thus far, the lathe is of conventional construction and hasnot included a description of the control system of the invention. Withsuch a conven-' tional lathe an operator could only change the thicknesssettings of the roller bar and knife as follows: 1. Assuming the gearbox arrangement as described, first the engaged gear on the A side andthe engaged gear on the B side of'decimal box 54 would be shiftedindividually and manually back to their neutral positions and a secondgear on the A side and a second gear on the B side shifted manually inthe necessary direction to give the desired new speed ratio.Furthermore, it would be necessary to manually shift operating lever 81of the two-speed gear box depending on whether the low or high speedrange would be required for the desired thickness setting. Thus theseveral manual and separate gear-shifting operations were in themselvestime consuming to change the rate of feed of knife 16. 2. The desiredhorizontal spacing of the roller bar relative to knife 16 would bechanged according to the new thickness of peel selected throughoperation of a relatively slow-speed drive from motor 32 to the rollerbarsubcarriage 30. 3. The operator would manually turn set screws 40 and41 to change the elevation of roller bar head 30 relative to knifecarriage 18, and thereby the spacing of roller bar 28 relativeto theknife as dictated by the changed thickness requirements. Naturally, theforegoing three separate manual steps are tedious and time consuming.understandably, they gave rise to the practice of peeling a singleconstant thickness of veneer for as long as possible without changingthickness settings and at least through the peeling of one entire log.Otherwise it would not be economical to shut down production to changefrom a thick to a thin setting or from a thin to a thick setting everytime a change in quality of the wood in a single log was observed.Although the foregoing prior practice is uneconomical and results inmuch wastage, in fact it is more economical than shutting downfrequently to change thickness settings.

Control System The control system of the invention comprises essentiallyfour elements. A first of these four elements is a means indicatedgenerally at 83 for shifting gear boxes 22 quickly from one preselectedspeed ratio to another.

The second of these elements comprises a means indicated generally at 85for changing quickly the horizontal spacing between roller bar 28 andknife 16.

The third of these elements includes means indicated generally at 87 forchanging quickly the vertical spacing between the roller bar and knife.

Finally the fourth element of the system is a remote control meansindicated generally at 89 for operating all three of the aforementionedelements substantially at the same time from a control station remotefrom such elements. A detailed description of each of the above fourelements follows.

Shifting Arrangement for Gear Boxes A series of conventional shiftingforks, one for each set of sliding gears, shifts each of the slidinggear sets 64 of gearbox 54 to the right or left on splined countershafts60, 62. From FIG. 4 it will be apparent that only one set of gears oneach of The A and B sides of the decimal gear box can be in mesh withone of the gears on input shaft 56 at any given time. Yet one gear oneach side of the box must be engaged to transmit power to the outputshaft. Thus one shifting fork on each of the A and B sides is operatedat a time.

Each shifting fork is shifted to shift a gear set right or left in FIG.4 by a pivotal shifting crank, the pivotal post portion 90 of each ofwhich is shown in FIGS. 5 and 6. Each post extends upwardly through twoshifting levels of the decimal gear box including a lower shifting level92, shown in FIG. 5, and an upper shifting level 94, shown in FIG. 6.The upper level is superimposed on the lower level and both levels inturn are superimposed on the interior of the decimal gearbox in themanner shown in FIG. 10.

Each shifting level of gear box 54 has an A and a B side correspondingto The A and B sides of the shiftable gear sets shown in FIG. 4. Eachpost 90 of the A and B sides of each of the upper and lower shiftinglevels is pivoted in a clockwise or counter clockwise direction to shiftits corresponding gear set to the right or left by a shift lever 96.

Each of the five shift levers 96 on each of the A and B sides of eachshifting level can be selectively connected by a removable pin 98 to oneof the four shift bars 100, 104, 108, 110 common to each of the foursets of five levers. Each shift bar can be shifted lengthwise inopposite directions to shift a connected lever to the right or left andthereby shift a corresponding fork and sliding gear set. Air cylinders102, 106, 112 and 114 shift the shift bars 100, 104, 108, 110,respectively, in the desired direction to engage the selected gears onthe A and B sides of the decimal gear box. However, it is important thatonly one of the two shift bars 100, 108 on the A side and one of the twoshift bars 104, 110 on the B side be shifted from its neutral positionat a timeso that only one gear oneach side is engaged at any time. Eachof the four shift bars 100, 104, 108, 110 is biased to a neutralposition, as shown, by a centering spring 1 16.

Each of the four air cylinders 102, 106, 112 and 114 is a double-actingcylinder capable of reciprocating its shift bar to the right or leftfrom its neutral position. However, in practice it is frequentlydesirable to prevent the shifting movement of a given shift bar in oneof its two directions, depending on the thicknesses selected, so as toprevent inadvertent selection of a wrong gear ratio. For this purpose apair of stop pin holes 118, 119 is provided in each shift bar, onepositioned on each of the opposite sides of an abutment member 120 whenthe shift bar is spring-centered to its neutral position. By inserting astop pin (not shown) through one of the pin holes 118, 119, shiftingmovement of the shift bar in one of its two directions of movement isprevented through abutment of the stop pin with the abutment member.Thus, for example, if the pin is inserted in hole 118 of shift bar 100in FIG. 5, cylinder 102 cannot shift the bar toward the right from itsneutral position. The converse would be true if the stop pin is insertedin hole 119.

A fifth double-acting air cylinder 122 is mounted on the side of thetwo-speed gear box 54. The piston rod of this cylinder is connected toclutch-operating lever 81 to shift the two-speed gear box from its highspeed range to its low speed range and back again. A solenoid valve 124controls the direction of air flow to cylinder 122.

Operation of the four shift bar operating cylinders I 102, 106, 112, 114is controlled by three air valves each. Cylinder 102 is controlled by apair of two-position on-off valves 102a, l02b and a directional controlvalve 1020. Cylinder 106 is controlled by the pair of onoff valves 106a,l06b and the directional control valve 106c. Cylinder 112 is controlledby the pair of on-off valves 112a, 112b and the directional controlvalve 1120. Cylinder 114 is controlled by the pair of on-off valves114a, 114b and the directional control valve l 140.

As will be clear from FIG. 7, valves 102e, 1060, and 1120 and 1140control the direction of movement of their respective cylinders and thusthe direction of shifting of the slidable gears. These valves aremanually operated and for convenience may be located at a remoteoperators station.

With reference to FIGS. 5, 6 and 7, air valves 102a and b, 106a and b,112a and b and 114a and b are operated by cams 125, 126 fixed to eachshaft bar. The two cams on each A shift bar operate the two air valves aand b for the other A shift bar. Similarly the two cams on each B shiftbar operate the a and b valves for the other B shift bar. Thisarrangement ensures that one of the two air cylinders on each of the Aand B sides of the decimal gear box returns to its centered neutralposition before the other of such two cylinders can shift from itsneutral position, thereby preventing the engagement of two A or two Bgears simultaneously and resulting damage to the gear box.

In FIG. 7 solenoid valve 124 is shown in a position for shifting clutchcylinder 122 to the left to thereby shift the two-speed gear box to itslow speed range for a relatively thin peel. The a and b valves forcylinders 102 and..l06 are shown in positions permitting air flowthrough their respective valves 102c and l06c to their shift barcylinders. 102 and .106 in a manner so that cylinder 102 and thusits'shift baris shifted toward the left and in'a manner so that cylinder106 and its shift bar are shifted toward the right. At the same time,the a and b valves for cylinders 112 and 114 are shown in positionsblocking flow to such cylinders. The latter cylinders remain centered intheir inactive positions until lower shift bars 100, 104 permit theirrespective air valves 1120, 112b, 1140, 114b to open through return ofcylinders 102 and 106 to their neutral positions. 6

From the description thus far, it will be clear that A shift bars 100and 108 shift the same five sets of gears inthe decimal gear box.Similarly, B shift bars 104' and l shift the same five sets of gears onthe B side of the decimal gear box. Each one of the ten shift levers 96for each shifting level may be said to have two positions which arenumbered 1 through 10 on the A side and 1 through 10 on the B side ofeach shifting level in each of FIGS. 5 and 6. Thus each lever 96 may bedesignated by a letter and numbers corresponding to the position it Ioccupies in its level of the gear box, such as lever Al-2, A7-8, 83-4,89-10, etc., as shown in FIGS. 5 and 6.

The desired thin and thick peels for a given run may require, forexample, that one of the levers A1-2 be moved to its A1 position forathin peel and that one of levers A5-6 be moved to its A6 position for athick peel. Since only one A lever can be connected to the same shiftbar 100 or 108 at a time to prevent shifting more than one'A gear at atime, it is necessary to provide two shift bars for the A side of thegear box. In the example, lever A1-2 would be connected by a pin to oneA shift bar, and lever A5-6 would be pinned to the other A shift bar.Forthesame reason, two B shift bars are provided.

Horizontal Adjustment of Roll Bar The illustrated means 85 for changingthe spacing between roller bar 28 and knife 16 in the direction ofmovement of the knife, or horizontally, includes a modification of thetransmission 36 to give a high and low speed drive for the roller bar.Referring to FIGS. 1

and 11, transmission 36 from electric motor 32 includes a drive shaft130 from the motor provided with two pneumatic clutches, including ahigh speed clutch 132 and a low speed clutch 134. When the high speedclutch is engaged and low speed clutch disengaged, the drive is throughchain-and-sprocket drive 136, countershaft 138, cross shaft 139 andbevel gears 140, 141

' to worm gear 34 which drives the roller bar ahead at a relatively highspeed to its desired position relative to the knife. This desiredposition can be readily deterrowhead 143a. For a thick peel the head ismoved in the reversedirection through reversal of motor 32 until marker142b is aligned with arrowhead 1430.

When a fine adjustment of the pressure of roller bar 28 against theveneer is desired, high speed clutch 132 is disengaged and low speedclutch l34is engaged to drive the worm shaft through chain-andsprocketdrive 144, countershaft 148, gears 145, 146, cross shaft and worm shaft139. This provides a very slow speed movement of the head 30, permittingthe desired fine adjustment of roller bar pressure.

Normally, when the roller bar is in a predetermined adjusted position,both high speed clutch 132 and low speed clutch 134 are engaged. Withboth clutches engaged they serve as a brake to hold the roller bar inits predetermined adjusted position relative to the knife.

The air circuit which controls operation of the pneumatic clutches isshown in the air circuit diagram of FIG. 7. Air under pressure from asource 148 is supplied through lines 149, 150 to a pair of normally opensolenoid valves 152, 154 to the high and low speed clutches so that bothclutches remain engaged simultaneously. When it is desired to operatethe high speed clutch, the low speed clutch is disengaged by energizingsolenoid valve 154 to shift it to the left in FIG. 7, throughappropriate electrical control means to be described. Conversely, when adrive is desired through the low speed clutch, the high speed clutch isdisengaged by energizing solenoid valve 152 to block the air supply tothe high speed clutch.

It will be appreciated that a variable speed electric or other motor orother type of variable speed transmission could be used in place of thetwo-speed pneumatic clutch-operated transmission described, to give 'thedesirable multiple speed drive for the horizontal roller bar feed.

Vertical Adjustment of Roller Bar A quick vertical adjustment of rollerbar 28 is made by vertical adjustment means 87 which includes a pair ofupright hydraulic cylinders 160, 161, both of which are shown in FIG. 8and one of which is shown in FIGS. 1 and 2. One of such pair ofcylinders is mounted at each of the opposite sides of roller bar head 30as shown in FIG. 2 within carriage 18. Thus each such cylinder moveshorizontally with the knife carriage.

. Each cylinder includes a ram 162 connected at its outer end to a yokemember 163 which abuts a lower surface of an abutment portion 164 ofroller bar head 30. Head 30 also includes an upper abutment portion 166.The upper adjustable stop screw 40 of carriage 18 is positioned aboveupper abutment portion 166 of head 30. The lower adjustable stop screw41 of carriage 18 is positioned beneath lower abutment portion 164 ofhead 30.

The stroke of the rams 162 of cylinders and 161 are such that when therams are extended, head 30 is raised until abutment portion 166 contactsthe lower end of upper stop screw 40 to determine the upper limitposition of roller bar 28. Conversely, when rams 162 are retracted, head30 is lowered until lower abutment portion 164 contacts the upper end oflower stop screw 41 to determinethe lower limit position of roller bar.

28. The upper and lower limit positions of the roller bar can be changedthrough threaded adjustment of the upper and lower stop screws.

FIG. 8 shows the hydraulic control circuit diagram for controllingoperation of the two lift cylinders 160, 161. Hydraulic fluid issupplied under pressure from a pump 168 driven by an electric motor 169through a supply line 170 and branch lines 171, 172 to upper ends of thecylinders or through alternate supply line 173 and branch lines 174, 175to the lower ends of the cylinders. A two-position solenoid valve 176 ina first position shown directs pressure fluid through lines 171 and 172to the upper ends of the lift cylinders to retract the same. In thesecond position of valve 176, supply fluid is directed through lines173, 174 and 175 to the lower ends of the lift cylinders to extend thesame. In either case, return flow is through return line 178 to sump179.

FIG. 8 also shows the hydraulic circuit driving the hydraulic motor 46which rotates the roller bar 28. Such circuit includes a pump 180 drivenby the same electric motor 169 that drives pump 168. Pump 180 suppliespressure fluid through supply line 181 to hydraulic motor 46. Returnflow is through line 182 back to sump.

Remote Control The remote control means 89 for operating the threeadjustments described is shown in FIGS. 1 and 9. The control, located ata control station remote from the three adjustment means, includes afirst toggle switch control member T81 and a second toggle switchcontrol member TS2. The single member toggle switch T82 is used to makeall three thickness change settings described. The single member toggleswitch TS] is used only for making slow-speed, fine pressure adjustmentsof the roller bar against the veneer being peeled.

As shown in the electrical diagram of FIG. 9, moving toggle TSl in onedirection, or upward in FIG. 9, energizes solenoid valve 152 todisengage high speed clutch 132 and energize motor 32 in a forwarddirection, thereby permitting low speed clutch 154 to drive roller barhead 30 slowly forward against the veneer.

Moving toggle TS1 downward again energizes solenoid valve 152 todisengage the high speed clutch and permit the low speed clutch to drivethe roller bar head slowly, but this time in a reverse direction throughactivation of motor 32 in reverse to back off the roller bar from theveneer. Release of toggle TSl returns it to its centered neutralposition.

Moving TS2 upward in FIG. 9 drives roller bar motor 32 in a forwarddirection, and at the same time energizes relay R1. Relay R1 closes thethree switches R1. Closing of one of these three switches energizes theA side of solenoid valve 124 to cause air cylinder 122 to shift thetwo-speed gear box into its low speed range for a relatively thin peel.At the same time, closing of a second of the three switches R1 energizessolenoid valve 154 to disengage low speed clutch 154, permitting highspeed clutch 152 to drive roller bar head 30 forward at a fast speed forquick readjustment of the horizontal position of the roller bar relativeto knife 16. When the desired horizontal adjustment of the roller bar ismade, the release of toggle TS2 returns it to its neutral position,thereby de-energizing solenoid valve 154 and re-engaging the low speedclutch to lock the roller bar in its readjusted position.

With TS2 in its upper position as mentioned, the third of the threeswitches R1 energizes the A side of solenoid valve 176 to directhydraulic flow to the upper ends of lift cylinders 160, 161, therebyretracting the cylinders and lowering the roller bar to itspredetermined lower limit position relative to knife 16.

All three of the above adjustments occur simultaneously. As soon as theyare made, toggle switch T82 is released and the lathe is reset and readyto produce a thin peel. Only a few seconds before, the lathe was set upfor producing a thick peel.

With toggle switch TS2 returned to its neutral position, the latheremains set for producing a predetermined thin peel until the sametoggle switch is moved downward to change the lathe settings for makinga predetermined thick peel.

By moving toggle T82 downward in FIG. 9, it activates roller bar motor32 in a reverse direction and energizes a second relay R2. Relay R2closes three cor- I responding switches R2 simultaneously to energizethe B side of solenoid 124, energize solenoid valve 154 and energize theB side of solenoid valve 176. The B side of solenoid valve 124 causesair cylinder 122 to shift the two-speed gear box into its high speedrange, thereby feeding the knife into the log at a fast speed to producea thick peel. At the same time, solenoid valve 154 again de-energizeslow speed clutch 154, permitting high speed clutch 152 to drive wormshaft 34 in a reverse direction to back off the roller bar to its thicksetting as detemiined by line-up of the marker l42b with the arrowhead1430 in FIG. 11. At the same time, the B side of solenoid valve 176directs hydraulic flow to the lower ends of lift cylinders 160, 161 toelevate roller bar 28 to its upper limit position. With this completed,

toggle switch T82 is released, permitting it to return to Operation Inpractice it has been found that the entire readjustment operation asdescribed can be accomplished in only a few seconds. This time factormakes it feasible.

for the first time to change thickness settings while peeling a singlelog, depending on the condition of the wood at-the surface being peeledat any given time. Thus, for example, if an outer portion of the log isrelatively free of defects, the lathe can be quickly adjusted forproducing a thin, high quality, valuable surface grade veneer relativelyfree of defects. However, if as the peeling progresses, a defectiveportion of the log is encountered, the lathe can be quickly adjusted fora thick peel merely by shifting toggle TS2 downwardly. Rotation of thelog thereafter will produce a thick core grade veneer. The thick peelcan be continued until such time as the quality of the wood at thesurface of the log improves sufficiently to again peel a thin surfacegrade veneer. Then the lathe can be adjusted quickly back to its thinsetting by shifting toggle TS2 upwardly from its neutral position.

Of course, it will be appreciated that the exact dimensions of the thinand thick peels that are produced through operation of toggle TS2 aredetermined by the gear ratios selected in the two gear boxes 54, 70. Theselection of necessary gear ratios to produce the desired dimensions ofthick and thin peels are made from a chart usually provided by the lathemanufacturer. From the chart, the necessary position dimensions can beselected.

To illustrate, let us assume that production schedul for a given millshift require a surface grade veneer of 0.032 of an inch and a coregrade veneer of 0.084 of an inch. The chart reveals that for therequired thin veneer, the two-speed box must be shifted to its low speedrange, and one of the A shift levers must be shifted to position A6 andone of the B levers must be shifted toposition B1 in the decimal gearbox. The

same chart shows thatffor the desired thick peel, the two-speed gear boxmust be shifted to its high speed range, and one of the A levers must beshifted to position A1 and one of the B levers must be shifted toposition B2.

To'accomplish the foregoing, lever A5-6 in lower shift level 92 of thedecimal gear box is pinned to shift bar 100. A stop pin is inserted instop hole 119 of the same shift bar so that such bar can only be shiftedtoward the right in FIG. 5 to shift lever A5-6 to its A6 position. Airvalve 1020 is positioned so that cylinder 10: will shift toward theright in FIG. 5 when the A side of solenoid valve 124 in FIG. 7 isenergized to shift the two-speed gear box into its lowrange.

Similarly, shift lever 81-2 at the lower shifting level 92 is pinned toshift bar 104, and a stop pin is inserted through stop pin opening 1 18of such shift bar so that it can only shift in a direction to positionlever 81-2 to its Bl position. Air valve 106c is positioned so that itwill cause cylinder 106 to shift left in FIG. 5 when the A side ofsolenoid valve 124 is energized to cause cylinder 122 to shift thetwo-speed gear box into its low speed range. The lower shifting level isnow set up to produce the desired thin peel.

- that air cylinder 112 will shift bar 108 toward the left and leverA1-2 to its Al position when the B side of solenoid valve 124 in FIG. 7is energized to shift the two-speed box into its high speed range. 0

Similarly lever B1-2 in the upper shifting level is pinned to shift bar1 10, and a stop pin is inserted in stop pin opening 119 of such bar sothat lever Bl-2 can be shiftedonly to its B2 position. Air valve 1 14cis set so as to cause cylinderll4 to shift bar 110' toward the right andthus shift lever 81-2 to its B2 position when the B side of solenoidvalve 124 is energized to shift the twospeed box into its low speedrange.

With the shifting levels set up as described, an up- A ward movement oftoggle TS2 will automatically set the lathe to peel veneer having athickness dimension of 0.032 of an inch. Similarly, a downward movementof toggle TS2 will automatically readjust'the lathe to peel veneerhaving a thickness dimension of 0.084 of an inch. Operation of cylinders102 and 106 to produce the thin peel automatically prevent operation ofcylin-' ders 1 12 and 114 by closing the a and b air valves of thelatter cylinders until the former cylinders return to their neutralpositions. The converse occurs when cylinders l 12 and l 14 areoperated.

Having illustrated what is now a preferred embodiment of our invention,it should be apparent to those having skill in the art that the samepermits of modificaat various predetermined speeds, a roller barpositioned with respect to the knife for applying a pressure to a backsurface of veneer as it is peeled from'the log, means mounting theroller bar for movement with the knife toward the log, said roller barmounting means also mounting the roller bar for movement in thedirection of knife movement independently of knife movement and formovement in a direction normal to the direction of knife movement, andmeans for moving said roller bar relative to said knife in the directionof knife movement,

a control system for quickly changing settings of the veneer lathe topeel different thicknesses of veneer from the same log or from differentlogs comprismg:

means for shifting quickly said multiple speed trans mission from afirst predetermined speed to a second predetermined speed to change thespeed of movement of said knife into said log,

v said means for moving said roller bar relative to said knife in thedirection of knife movement including variable speed means for movingsaid roller bar at a first fast speed for quick adjustmentof said rollerbar relative to said knife and at a second slow speed for adjusting thepressure of the roller bar against the back of the veneer.

2. Apparatus according to claim 1 including remote manual control meansfor operating said shifting means and said variable speed means from aposition remote from said shifting and variable speed means.

3. Apparatus according to claim 1 including means for changing quicklythe spacing between said roller bar and said knife in a direction normalto the direction of knife travel.

4. Apparatus according to claim 3 including remote manual control meansfor operating said shifting means, said variable speed means and saidspacing changing means from a control station remote from all three ofsaid means.

5. Apparatus according to claim 2 wherein said remote control meansincludes a single control member for operating said shifting means andfor actuating said variable speed means to move said roller bar at saidfirst fast speed.

6. Apparatus according to claim 4 wherein said remote control meansincludes a single control member for operating said shifting means, foractuating said variable speed means to move said roller bar at said fastspeed and for operating said spacing changing means.

7. A control system for quickly adjusting a veneer lathe to change thethickness of peel from f a -log, wherein said lathe includes means forrotating a log, a knife movable into the log, and a roller bar spacedfrom the knife for applying pressure to the back side of veneer as it ispeeled from the log, said control system including:

means for quickly changing the speed of movement of said knife into saidlog, and means for quickly changing the spacing between the cutting edgeof said knife and said roller bar in both the direction of knifemovement and in a direction normal to the direction of knife movement.8. A system according to claim 7 including manually operable remotecontrol means for selectively operating said knife speed changing meansand said roller bar spacing changing means from a position remote fromboth said changing means.

9. A system according to claim 8 wherein said remote control meansincludes a single control member for effecting all three changessimultaneously.

10. In a veneer lathe including means for mounting and rotating a log tobe peeled, a knife having a cutting edge for peeling said log, a rollerbar adjacent the cutting edge of said knife for applying a pressure to aback surface of veneer at the log as it is peeled from the log, knifefeed means for moving the knife and roller bar together toward the log,and means providing multiple thickness settings for said lathe so thatveneer of at least several different predetermined multiple thicknessescan be peeled,

adjustment means for quickly changing the thickness settings of saidlathe between a first thin setting and a second thick setting so thatboth surface and core grade veneer can be peeled from a single log, saidadjustment means comprising: means for changing quickly the feed rate ofsaid knife between a first preset slow rate for a thick peel and asecond preset fast rate for a thin peel,

means for changing quickly the spacing between said roller bar and saidknife cutting edge in the direction of knife movement between a firstpredetermined maximum spacing for a thick peel and a secondpredetermined minimum spacing for a thin peel,

means for changing quickly the spacing between said roller bar and saidknife cutting edge in a direction normal to the direction of knifemovement between a first preset maximum spacing for a thick peel and asecond preset minimum spacing for a thin peel,

and manually operable control means for actuating all three of saidchanging means and thereby effecting all three of said changessimultaneously.

11. Apparatus according to claim 10 including means for changing slowlythe spacing between said roller bar and said knife cutting edge in thedirection of knife movement for fine adjustment of the back pressure ofsaid roller bar against the veneer.

12. Apparatus according to claim 11 wherein said means for changing thespacing between said roller bar and said knife cutting edge quickly andslowly in the direction of knife movement include a constant speed motorand a multi-speed drive transmission means interconnecting said motorand said roller bar, said transmission means including a normallyengaged highspeed transmission path including a first clutch means and anormally engaged low-speed transmission path including a second clutchmeans arranged such that when both said clutching means are engaged,said transmission means is locked to prevent the transmission of drivingforce to said roller bar, said control means including means forselectively disengaging either one of said first and second clutch meansso that said transmission path having the engaged one of said clutchmeans transmits driving force to said roller bar.

13. Apparatus according to claim 10 wherein said knife feed meansincludes a drive means and transmission means for transmitting motivepower from said drive means to said knife, said means providing multiplethickness settings for said lathe including a multiple speed gear boxmeans having multiple selectively engageable shiftable gears providing amultiplicity of different output speeds for feeding said knife into alog at different feed rates, said means for changing quickly the feedrate of said knife including means for programming two different gearcombinations for engagement from said multiple shiftable gears to selectalternatively two different output speeds from said multiplicity ofoutput speeds, and means operable automatically upon actuation of saidcontrol means for shifting preselected ones of said gears of said gearbox means to provide selectively one or the other of said gearcombinations and therefore one or the other of said two selected outputspeeds and knife feed rates.

14. A thickness control for a veneer lathe having a knife which can befed into a rotating log at a multiplicity of different speeds to peeldifferent thicknesses of veneer by a knife drive means including amultiplespeed gear box having an input shaft, an output shaft and firstand second countershafts in driving engagement with said output shaftthrough differential gearing, said countershafts being parallel to saidinput shaft with a plurality of shiftable gears on each countershaftselectively engageable with gears on said input shaft for transmittingmotive power at a multiplicity of different rotational speeds to saidoutput shaft, and a separate gear shifter means for each said shiftablegear on each said countershaft operable to shift an associated saidshiftable gear in opposite directions along its said countershaft, saidthickness control comprising:

first and second pairs of shift bar means,

said first pair including first and second shift bar means eachselectively connectable to any one of said gear shifter means for saidfirst countershaft for shifting selected shiftable gears on said firstcountershaft from a neutral position in either of opposite directionsinto engagement with said input shaft gears,

said second pair including third and fourth shifter bar means eachselectively connectable to any one of said gear shifter means for saidsecond countershaft for shifting selected shiftable gears on said secondcountershaft from a neutral position in either of opposite directionsinto engagement with said input shaft gears,

a separate shifter bar actuating means for each said shifter bar meansfor moving each said shifter bar means independently of the others ofsaid shifter bar means selectively in either of opposite directions forshifting a connected said shiftable gear in a corresponding direction,and control meansfor selectively controlling the operation of said fourshifter bar actuating means including:

a manually selective directional control means for each said shifter baractuating means for determining the direction of .movement of anassociated said shifter bar means and thus the direction of shifting ofa connected shiftable gear means upon operation of the associated saidactuating means,

, on-off control means for each said shifter b'ar actuating meansoperable automatically to prevent the operation of the actuating meansfor one said shifter bar means of a pair when the actuating means forthe other said shifterbar means of the same said pair is actuated,

and manually operable speed shifting means movable to a first positionfor operating a said actuating means for one said shifter bar means ofeach said pair shifter bar means to provide a preselected first gearratio and output speed and movable to a second position for operating asaid actuating operable in said first position to shift said two-speedmeans for the other said shifter bar means of each gear box to itslow-speed range and thereby provide a preselected slow output speed andthin peel and operable in said second position to shift said two-speedgear 7 box to its high-speed range and thereby provide a preselectedhigh output speed and thick peel of veneer.

16. A thickness control according to claim 14 wherein said shifter barmeans include four shifter bars mounted for reciprocation, saidactuatingmeans for each shifter bar including a double-acting fluid-actuatedcylinder, said directional control means including a manuallypositionable two-position directional controlvalve for each saidcylinder, said on-offcontrol means including a pair of on-off controlvalves for each cylinder, one in a fluid passage leading to each side ofthe associated said cylinder, each said on-off valve of a cylinder forone shifter bar of a pair being movable to an off position upon movementof the other shifterbar of a pair from a neutral position to agear-shifting position.

17. A thickness control according to claim 16 wherein said control meansincludes a releasable stop said speed-shifting means.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,680,613 Dated August 1 1972 Inventods) Curtice F. Daniels and CurticeF. Daniels Jr.

It is certified that error appears in the above-identified patent andthat said Letters Patent are hereby corrected as shown below:

In the references, "Class 14/213" should be --l44/2l3. Column 4, line 4"while countershaft" should be -lO0-. Column 4, line 15, after (notshown) insert --into mesh with one of two sets of stationary gears onthe input shaft..

Column 5, line 33, "The" should be -the-. Column 5, line 51, "The"should be -the---.-- Column 9, line 60, "horizOntal" should be-horizontal--. Column 15, line 21 (claim 14) after "pair" insert of.

Signed and sealed this 9th day of January 1973.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissionerof Patents FORM P0405) (10'69) USCOMM DC 60376 P69 a U.5 GOVERNMENTPRINTING OFFICE: I959 O366'334

1. In a veneer lathe including means for rotating a log to be peeled,means mounting a knife for movement into the log, means including adrive motor and multiple speed transmission for moving the knife intothe log at various predetermined speeds, a roller bar positioned withrespect to the knife for applying a pressure to a back surface of veneeras it is peeled from the log, means mounting the roller bar for movementwith the knife toward the log, said roller bar mounting means alsomounting the roller bar for movement in the direction of knife movementindependently of knife movement and for movement in a direction normalto the direction of knife movement, and means for moving said roller barrelative to said knife in the direction of knife movement, a controlsystem for quickly changing settings of the veneer lathe to peeldifferent thicknesses of veneer from the same log or from different logscomprising: means for shifting quickly said multiple speed transmissionfrom a first predeterMined speed to a second predetermined speed tochange the speed of movement of said knife into said log, said means formoving said roller bar relative to said knife in the direction of knifemovement including variable speed means for moving said roller bar at afirst fast speed for quick adjustment of said roller bar relative tosaid knife and at a second slow speed for adjusting the pressure of theroller bar against the back of the veneer.
 2. Apparatus according toclaim 1 including remote manual control means for operating saidshifting means and said variable speed means from a position remote fromsaid shifting and variable speed means.
 3. Apparatus according to claim1 including means for changing quickly the spacing between said rollerbar and said knife in a direction normal to the direction of knifetravel.
 4. Apparatus according to claim 3 including remote manualcontrol means for operating said shifting means, said variable speedmeans and said spacing changing means from a control station remote fromall three of said means.
 5. Apparatus according to claim 2 wherein saidremote control means includes a single control member for operating saidshifting means and for actuating said variable speed means to move saidroller bar at said first fast speed.
 6. Apparatus according to claim 4wherein said remote control means includes a single control member foroperating said shifting means, for actuating said variable speed meansto move said roller bar at said fast speed and for operating saidspacing changing means.
 7. A control system for quickly adjusting aveneer lathe to change the thickness of peel from a log, wherein saidlathe includes means for rotating a log, a knife movable into the log,and a roller bar spaced from the knife for applying pressure to the backside of veneer as it is peeled from the log, said control systemincluding: means for quickly changing the speed of movement of saidknife into said log, and means for quickly changing the spacing betweenthe cutting edge of said knife and said roller bar in both the directionof knife movement and in a direction normal to the direction of knifemovement.
 8. A system according to claim 7 including manually operableremote control means for selectively operating said knife speed changingmeans and said roller bar spacing changing means from a position remotefrom both said changing means.
 9. A system according to claim 8 whereinsaid remote control means includes a single control member for effectingall three changes simultaneously.
 10. In a veneer lathe including meansfor mounting and rotating a log to be peeled, a knife having a cuttingedge for peeling said log, a roller bar adjacent the cutting edge ofsaid knife for applying a pressure to a back surface of veneer at thelog as it is peeled from the log, knife feed means for moving the knifeand roller bar together toward the log, and means providing multiplethickness settings for said lathe so that veneer of at least severaldifferent predetermined multiple thicknesses can be peeled, adjustmentmeans for quickly changing the thickness settings of said lathe betweena first ''''thin'''' setting and a second ''''thick'''' setting so thatboth surface and core grade veneer can be peeled from a single log, saidadjustment means comprising: means for changing quickly the feed rate ofsaid knife between a first preset ''''slow'''' rate for a thick peel anda second preset ''''fast'''' rate for a thin peel, means for changingquickly the spacing between said roller bar and said knife cutting edgein the direction of knife movement between a first predetermined''''maximum'''' spacing for a thick peel and a second predetermined''''minimum'''' spacing for a thin peel, means for changing quickly thespacing between said roller bar and said knife cutting edge in adirection normal to the direction of knife movement between a firstpreset maximum spacing for a thick peel and a second preset minimumspacing for a thin peel, and manually operable control means foractuating all three of said changing means and thereby effecting allthree of said changes simultaneously.
 11. Apparatus according to claim10 including means for changing slowly the spacing between said rollerbar and said knife cutting edge in the direction of knife movement forfine adjustment of the back pressure of said roller bar against theveneer.
 12. Apparatus according to claim 11 wherein said means forchanging the spacing between said roller bar and said knife cutting edgequickly and slowly in the direction of knife movement include a constantspeed motor and a multi-speed drive transmission means interconnectingsaid motor and said roller bar, said transmission means including anormally engaged high-speed transmission path including a first clutchmeans and a normally engaged low-speed transmission path including asecond clutch means arranged such that when both said clutching meansare engaged, said transmission means is locked to prevent thetransmission of driving force to said roller bar, said control meansincluding means for selectively disengaging either one of said first andsecond clutch means so that said transmission path having the engagedone of said clutch means transmits driving force to said roller bar. 13.Apparatus according to claim 10 wherein said knife feed means includes adrive means and transmission means for transmitting motive power fromsaid drive means to said knife, said means providing multiple thicknesssettings for said lathe including a multiple speed gear box means havingmultiple selectively engageable shiftable gears providing a multiplicityof different output speeds for feeding said knife into a log atdifferent feed rates, said means for changing quickly the feed rate ofsaid knife including means for programming two different gearcombinations for engagement from said multiple shiftable gears to selectalternatively two different output speeds from said multiplicity ofoutput speeds, and means operable automatically upon actuation of saidcontrol means for shifting preselected ones of said gears of said gearbox means to provide selectively one or the other of said gearcombinations and therefore one or the other of said two selected outputspeeds and knife feed rates.
 14. A thickness control for a veneer lathehaving a knife which can be fed into a rotating log at a multiplicity ofdifferent speeds to peel different thicknesses of veneer by a knifedrive means including a multiple-speed gear box having an input shaft,an output shaft and first and second countershafts in driving engagementwith said output shaft through differential gearing, said countershaftsbeing parallel to said input shaft with a plurality of shiftable gearson each countershaft selectively engageable with gears on said inputshaft for transmitting motive power at a multiplicity of differentrotational speeds to said output shaft, and a separate gear shiftermeans for each said shiftable gear on each said countershaft operable toshift an associated said shiftable gear in opposite directions along itssaid countershaft, said thickness control comprising: first and secondpairs of shift bar means, said first pair including first and secondshift bar means each selectively connectable to any one of said gearshifter means for said first countershaft for shifting selectedshiftable gears on said first countershaft from a neutral position ineither of opposite directions into engagement with said input shaftgears, said second pair including third and fourth shifter bar meanseach selectively connectable to any one of said gear shifter means forsaid second countershaft for shifting selected shiftable gears on saidsecond countershaft from a neutral position in either of oppositedirections into engagement with said input shaft gears, a separateshifter bar actuating means for each said shifter bar means for movingeach said shiFter bar means independently of the others of said shifterbar means selectively in either of opposite directions for shifting aconnected said shiftable gear in a corresponding direction, and controlmeans for selectively controlling the operation of said four shifter baractuating means including: a manually selective directional controlmeans for each said shifter bar actuating means for determining thedirection of movement of an associated said shifter bar means and thusthe direction of shifting of a connected shiftable gear means uponoperation of the associated said actuating means, on-off control meansfor each said shifter bar actuating means operable automatically toprevent the operation of the actuating means for one said shifter barmeans of a pair when the actuating means for the other said shifter barmeans of the same said pair is actuated, and manually operable speedshifting means movable to a first position for operating a saidactuating means for one said shifter bar means of each said pair shifterbar means to provide a preselected first gear ratio and output speed andmovable to a second position for operating a said actuating means forthe other said shifter bar means of each said pair to provide apreselected second gear ratio and output speed.
 15. A thickness controlaccording to claim 14 wherein said knife drive means includes atwo-speed gear box connected in tandem with said multiple speed gearbox, said speed shifting means including means operable in said firstposition to shift said two-speed gear box to its low-speed range andthereby provide a preselected slow output speed and thin peel andoperable in said second position to shift said two-speed gear box to itshigh-speed range and thereby provide a preselected high output speed andthick peel of veneer.
 16. A thickness control according to claim 14wherein said shifter bar means include four shifter bars mounted forreciprocation, said actuating means for each shifter bar including adouble-acting fluid-actuated cylinder, said directional control meansincluding a manually positionable two-position directional control valvefor each said cylinder, said on-off control means including a pair ofon-off control valves for each cylinder, one in a fluid passage leadingto each side of the associated said cylinder, each said on-off valve ofa cylinder for one shifter bar of a pair being movable to an offposition upon movement of the other shifter bar of a pair from a neutralposition to a gear-shifting position.
 17. A thickness control accordingto claim 16 wherein said control means includes a releasable stop meansfor each shifter bar operable when engaged to selectively prevent themovement of said shifter bar in either direction from a neutral positionand thereby operable to determine which said shifter bar of a pair isoperated in each of the two different speed modes of said speed-shiftingmeans.